Process of manufacturing iron or steel



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EUGENE H. COVLES, OF CLEVELAND, OHIO.

PROCESS OF 'iViANUFACTURlNG BRQN OR STEEL.

SPECIFICATION forming part of Letters Patent No. 397,491, dated February12, 1889.

Application filed December 24, 1887. Serial No. 258,920. (No specimens.)

To all whom it may concern.-

Be it known that LEUGENE H. COWLES, of Cleveland, in the county ofCuyahoga and State of Ohio, have invented a certain new and ImprovedProcess of Manufacturing Iron or Steel; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such aswill enable others skilled in the art to which it pertains tomake and use the same.

My invention relates to a new process of improving ,iron and steel; andit consists in steps hereinafter described and claimed.

It is well known that many metals when hot have a great affinity forcertain elements that exist in a gaseous state in the atmosphere towhich they are exposed while in a molten condition. In the smelting andmanufacture of iron and steel oxygen appears to be the most noxious andinjurious element encountered. hen fluid, the iron takes up largequantities of oxygen, either in a free state or combined with otherelements-such as can bouand the oxygen or carbon oxide remains in themetal either in mechanical mixture or in the state of chemicalcombination with the iron even after the metal has become cold. Theworst effect of oxygen thus found in iron or steel is the formation ofcertain sub-oxides of iron and the leaving of cavities through the mass,whose sides are lined with the suboxide or streaks, seams, fissures, andflaws in rolled or forged iron or steel which are caused by thenon-weldin g character of the sub-oxide that forms on the faces of thesescams or cracks. Thepresence of the sub-oxide throughout mass of iron orsteel in minute specks that can only be seen by the microscope likewiseseriously impairs the strength, hot and cold working qualities, andwelding properties of iron and steel. In fact, it is susceptible ofproof that the sub-oxide that forms in iron and steel is more disastrousto its Value than the so-called blowholes. In order to prevent thesesub-oxides from forming and to eliminate as far as possible the badeffects of oxygen and other injurious elementssuch, for instance, assulphurfrom iron or steel,l use an alloy of silicon and aluminium. Thisalloy of aluminium and silicon is somewhat variable in its proportions;but it has been found that the silicon may form as high as fiftypercent. of the alloy. If this alloy be added to iron or steel while ina fluid state, or melted together with iron or steel, or reduceddirectly from the cres of silicon and aluminium into iron or steel, itwill remove nearly all the oxygen. present. It may likewise be addedto abath of molten iron or steel in the form of an alloy of silicon,aluminium, and iron or steel.

By the application of this invention and subsequent thereto many tens ofiron or steel are now being refined and improved weekly in this countryand abroad, and it is found that it is a much cheaper process than thatwherein pure aluminium or an alloy of aluminium and iron is used toeffect a somewhat similar result. The preferable manner of using thisinvention is to treat a bath of iron or steel while in the furnace orconverter with a small percentage of aluminium and silicon alloy, oralloy of the same with iron, the same to contain not to exceed one-fifthof one per cent. of aluminium and silicon combined, the same to bemelted together with the iron or steel, in order to give the aluminiumand silicon sufficient time to thoroughly mix with the entire mass ofmaterial to be treated. If the metal is immediately taken from the fireas soon as the aluminium and silicon is well incorporated, the bestresults will be obtained; but should the heat be prolonged, and it isdesired to take extra precautions, another five-hiuidredths of one percent. of aluminium and silicon combined may be added, alone or alloyedwith iron, to the material, if it be still fluid after it leaves thefurnace; but care should be taken to have the bath of molten metal to betreated superheated before leaving the furnace if an alloy of iron,silicon, and aluminium is to be used, as it has a very highmelting-point, and without such superheating it may chill the bath ofsteel or iron to which it is added.

I am fully aware that aluminium has heretofore frequently been added toiron and steel. It is claimed that traces of it have been found inlVootz steel and many other irons and steels; but these claims are ofdoubtful authenticity. Yet it has been frequently added to steel andiron in its pure state. Deville, Dr. Percy, and Sir Lothian Bell haveall made alloys of iron and steel with pure aluminium;

and hence I do not claim an alloy of iron or steel and aluminium, normethods of treating iron or steel with aluminium or alloy of aluminiumand iron.

An alloy of silicon and aluminium is much more economic and producesbetter results than the use of aluminium alone or combined with iron.

In reducing silicon and aluminium to form the desired alloy it is moreconvenient to add more or less iron for purpose of collecting theselight materials in the furnace where they are reduced, and consequentlysuch alloy of the three elements is more frequently used in carrying outmy invention than an'alloy of silicon and aluminium alone.

What I claim is 1. The herein-described step in the process ofmanufacturing iron and steel, consisting in the admixture with themolten iron or steel of an alloy of silicon and aluminium in about 1161proportions specified, substantially as set ort 1.

2. The herein-described step in the process of manufacturing iron andsteel, consisting in melting together iron or steel with an alloy ofsilicon, aluminium, and iron, substantially as set forth.

3. The herein-described step in the process of manufacturing iron andsteel, consisting in melting together iron or steel with an alloy ofsilicon and aluminium.

4. The herein-described step in the process of manufacturing iron andsteel, consisting in the admixture with the molten iron or steel of analloy of silicon, aluminium, and iron, substantially as set forth.

In testimony whereof I sign this specification, in the presence of twowitnesses, this 21st day of December, 1887.

EUGENE H. cowLEs.

Vitnesses:

ALBERT E. LYNCH, CHAS. II. DORER.

